Aug 9 (Reuters) - Meta Platforms' Threads app is adding new updates including the ability to share posts through Instagram messages, CEO Mark Zuckerberg said on Wednesday, as the company tries to retain users on its new app. Meta is looking at adding more "retention-driving hooks" to entice users to return to the app, like "making sure people who are on the Instagram app can see important Threads," Chief Product Officer Chris Cox had said at an internal company town hall in July, the audio of which was heard by Reuters. Meta is looking at adding more "retention-driving hooks" to entice users to return to the app, like "making sure people who are on the Instagram app can see important Threads," Chief Product Officer Chris Cox had said at an internal company town hall in July, the audio of which was heard by Reuters